Pyrimidines zinc complexes

Just zinc complexes bearing redox-active ligands sometimes display apparently reversible redox processes. Really, in these cases the electron transfer processes are centred on the ligand. This is, for example, the case of [Zn(papm)Cl2] (papm = 2-(phenylazo)pyrimidine), the (distorted) trigonal bipyramidal molecular structure of which is illustrated in Figure 134.194... 

Synthesis of copper and zinc complexes of 5,7-dimethyl-l,2,4-triazolo [l,5-a]pyrimidine has been reported [93AX(C)1902 94AX(C)510], Reaction of copper(II) thiocyanate with 5,7-dimethyl-l,2,4-triazolo[l,5-a]-pyrimidine (l) gave three different complexes two isomers of [Cu(NCS)2L2]2 and Cu(NCS)2L2 H20 (84IC2803). The mononuclear complexes, bis(thiocyanato-N)bis(6-methyl-l,2,4-triazolo[l,5-a]pyrimidine-jV-3)copper(II) and the polynuclear pseudo-layered complexes, bis(thio-cyanato-A0bis(5-methyl-l,2,4-triazolo[l,5-a]pyrimidine-A -3)copper(II) were prepared (89POL2313). 

Study of the zinc complex. It has been demonstrated that the metal is bonded to N-3 of the pyrimidine ring, not to the sulfur atom. ... 

Chemistry and biochemistry of insulin-mimetic vanadium and zinc complexes (including pyridine, pyrimidine, thiazole, and porphyrin derivatives) 06BCJ1645. 

Crystalline complexes were formed from ethyl 6-melhyl-4-oxo-6,7,8.9-tetrahydro-4//-pyrido[1.2-ci]pyrimidine-3-carboxylate and zinc chloride75 and from the quaternary salt (280) and mercuric potassium iodide.335 337... 

Ruthenium(II) A range of complexes of the type [Ru(L)(NH3)j] + (e.g. L = pyridine, pyridazine, pyrazine, pyrimidine,triazine, 2-cyanopyridine, 3-cyanopyridine, 4-cyan-opyridine, 2-, 3- and 4-RC(0)-substituted pyridines (R = CHMe2, CH2Et, CHjPr, OMe, NH2, OH, H, Ph ), IV-methylpyrazine, 4,4 -bipyridine, l,2-bis(4 -pyridyl)ethylene," hyp-oxanthine, guanine, xanthine,4-dimethylaminopyridine" ) have been prepared by reaction of [RuCl(NH3)j]Cl2 with a Ag" salt (AgOjCCF3 is often used) followed by zinc amalgam reduction... 

---